Edwaed p



(No Model.)

E. P. THOMPSON.

PROCESS OF TREATING- FILAMENTS FOR INGANDESGENT ELECTRIC LIGHTS.

No. 369,267. Patented Aug. 80, 1887.

Q V'vbmeooco (11 110 on lo a UNITED STATES PATENT rrrcn.

EDYVARD P. THOMPSON, OF ELIZABETH, NEW JERSEY.

PROCESS OF TREATING FlLAMENTS FOR INCANDESCENT ELECTRIC LlGHTS.

SPECIFICATION forming part of Letters Patent No. 369,267, dated August30, 1887.

Application filed September 15, 1886. Serial No. 213,574. (No model.)

To all whom it may concern:

Be it k uown that I, EDWARD P. THoMPsoN, a citizen of the United States,residingin Elizabeth, in the county of Union and State of New Jersey,have invented certain new and useful Improvements in Process of TreatingFila ments for Incandescent Electric Lights, of which the following is aspecification.

The invention relates to the process of treating filaments withsaccharine matter before they are carbonized. It has been foundadvantageous to soak the filaments in a saccharine solution before theyare placed in the carbonizing crucible or kiln. There is more or lessinconvenience experienced from the tendency of the filaments to stick tothe carbon of the mold by reason of the moist condition of the filament.

My invention consists in coating the saturated filament with a film ofwax, which effectually prevents the filaments from sticking to the mold.

In the accompanying drawing there is represented an apparatus adapted tocarry out the invention.

Referring to the drawing, A represents a vat containing a reel, 13, uponwhich the filament is wound. The vat contains an acidolated saccharinesolution, and the filament thus becomes thoroughly soaked. As it iswithdrawn from the reel it passes into and through a trough or tank, 0,being held down by rollers c c. This trough or tank contains melted wax.The heat of the wax drives off the water which is brought over from thevat A, and a film of the wax is deposited upon the filament. Adivision-wall, D, is placed near the end of the tank 0, at which thefilament passes out to a reel, E. The filament passes through a hole ordie, d, in this wall, and this hole is of such size as to remove themoisture from the filament and compress the fibers. Before leaving thetank, however, it passes through another bath of melted wax in thecompartment E, beyond the wall D, and under a roller, (2, and a thinfilm of wax is thus left on the filament as it is wound upon the reel E.This film or coating of wax effectually prevents the filament fromsticking to the mold during the process of carbonizing, and also bindsthe fibers closely against the filament, thus giving a more solid andfirmer product. The die d assists in insuring a compactness upon thepart of the filament. During the process of baking the wax vaporizes,and the vapor prevents the oxidation of the filament as it displaces theair.

The melted-wax bath may be advantageously used in treating filamentswhich have not been placed in a saccharine bath, as the wax serves tobind the fibers of the filament.

Other material than wax may sometimes be employed.

I claim as my invention 1. The hereinbefore described process oftreating filaments for incandescent electric lights, which consists insubjecting the filament to a bath of saccharine matter, and subsequentlypassing it through a bath of melted wax.

2. The hereinbefore described process of treating filaments forincandescent electric lights, which consists in treating the filament toa saccharine solution, subsequently passing it through a bath of meltedwax, and passing it from the wax bath through a die, substantially asdescribed.

3. The hereinbefore described process of treating filaments forincandescent electric lights, which consists in treating the filament toa saccharine solution, subsequently passing it through a bath of meltedwax, and passing it from the wax bath through a die, substantially asdescribed.

In testimony whereof I have hereunto subscribed my name this 17th day ofAugust, A. D. 1886.

EDWAED I THOMPSON.

Witnesses:

DANL. XV. Enenconn, GnAnLns A. TERRY.

